1. Field of the Invention
The present invention relates to a stitch size controllable knitting machine for forming a knitted fabric by taking in and out sinkers to/from between reciprocating knitting needles, and to a manufacturing method of knitted fabric.
2. Description of the Related Art
A conventional circular knitting machine or hosiery circular knitting machine includes a stitch size controlling sinker, as described in JP 2004-316000A, for example. FIGS. 31A and 31B show an exemplary conventional stitch size controlling sinker and an actuator, respectively. Referring to FIG. 31A, each stitch size controlling sinker 201 has one of a plurality of selector butts 202 to 205 which can be pressed when the corresponding stitch size controlling sinker 201 is selected. In the example of FIG. 31A, four selector butts 202 to 205 are arranged at different levels in a height direction of the knitting machine. That is, the selector butts 202-205 of adjacent stitch size controlling sinkers are arranged at different levels in the height direction.
As shown in FIG. 31B, when a selector head 207 of the actuator 206 comes into contact with the selector butt 202, the corresponding stitch size controlling sinker 201 is pushed out, i.e., selected. The selected stitch size controlling sinker 201 is therefore arranged at a position different from non-selected stitch size controlling sinkers 201. In accordance with the position of the stitch size controlling sinker 201, an arrangement of knitting yarns is changed, thus enabling the stitch size to be changed.
A knitting machine enabling the stitch size to be changed on a stitch-by-stitch basis has been required to have improved productivity. By increasing a rotation speed of a cylinder holding knitting needles, the productivity can be also improved. However, increasing the rotation speed of the cylinder can cause failure or omission of selection of the selector butt. Moreover, with the increase in the rotation speed of the cylinder, the movement of the actuator also has to be accelerated. If the number of the selector butts is increased, a space between adjacent selector butts arranged at the same level can be ensured. Therefore, increasing the number of the selector butts and reliable selection of the selector butts are required to correspond to the speed-up of the rotation of the cylinder.
However, in the conventional knitting machine described above, the selector butts are arranged at a plurality of different levels along a vertical direction parallel to the rotation axis of the cylinder. This makes it difficult to increase the number of the selector butts in the vertical direction and therefore an increase in the rotation speed of the cylinder is difficult.